1. Field of the Invention
The control of insects is of vital importance in the increasingly populous world of today. It is well known that insects such as those belonging to the orders of Lepidoptera, Coleoptera, Diptera, Homoptera, Hemiptera and Orthoptera, at the larval stage, cause extensive damage to many crops, for example, food crops and fibrous crops. Control of such insects contributes to the well-being of mankind by increasing the supplies of food and of the fibrous materials useful in the production of clothing.
2. Description of the Prior Art
In the prior art, Wellinga et al., U.S. Pat. No. 3,748,356 (July 24, 1973), describe a series of substituted benzoylureas which are taught as having strong insecticidal activity. The Wellinga et al. compounds are generally 1-(2,6-dichlorobenzoyl)-3-substituted phenyl)ureas, but also include several 1-(2,6-dichlorobenzoyl)-3-(substituted pyridyl)ureas.
Also in the prior art, Wellinga et al., U.S. Pat. No. 3,989,842 (Nov. 2, 1976), teach and claim insecticidal compositions and a method of controlling insects in agriculture and horticulture utilizing certain N-(2,6-dihalobenzoyl)-N'-(substituted phenyl)urea compounds as the active ingredient, as well as several N-(2,6-dichlorobenzoyl)-N'-(substituted pyridyl)ureas.
Other N-(2,6-dihalobenzoyl)-N'-(substituted phenyl)urea compounds are disclosed and claimed in Wellinga et al., U.S. Pat. No. 3,933,908 (Jan. 20, 1976), which compounds are disclosed as having insecticidal activity.
A number of prior art references discuss the insecticidal activity of 1-(2,6-dichlorobenzoyl)-3-(3,4-dichlorophenyl)urea. See Van Daalen et al., Die Naturwissenschaften 59, 312-313 (1972); Post et al., ibid. 60, 431-432 (1973); Mulder et al., Pestic. Sci. 4, 737-745 (1973).
Also, studies in the inhibition of the development of mosquitoes and houseflies, and of the control of alfalfa weevil, by the action of 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea are reported by Jakob, J. Med. Ent. 10. 452-455 (1973), and Neal, Jr., J. Econ. Ent., 67, 300-301 (1974), respectively.
Yet another prior art reference is Sirrenberg et al., U.S. Pat. No. 3,992,553 (Nov. 16, 1976), which discloses and claims mono-o-chloro-substituted benzoylureido-diphenyl ethers, alleged to posses excellent insecticidal activity against plant pests and as ectoparasitic agents in the veterinary medicine field.
Also in the prior art is Belgian Pat. No. 833,288 (Mar. 11, 1976), which teaches and claims disubstituted benzoyl pyrazinylureas having activity as insecticides.
Still another prior art reference is Belgian Pat. No. 838,286, directed to 1-benzoyl-3-(4-phenoxyphenyl)ureas alleged to possess insecticidal activity with low mammalian and plant toxicity.